Students create a physical model illustrating soil water balance using drinking glasses to represent the soil column, and explain how the model can be used to interpret data and form predictions. Using data from the GLOBE Data Server, they calculate...(View More) the potential evapotranspiration, average monthly temperatures and precipitation for their model. This is a learning activity associated with the GLOBE hydrology investigations and is supported by the Hydrology chapter of the GLOBE Teacher's Guide.(View Less)